The shrouds pull up the deck and that wants to squeeze the boat and the beam wants to decrees while the cabin top is pushed up. The two brackets you see are to fix the cabin topís height and keep the boat from distorting. You also need wedges or something like spartight to fix the position of the mast in the partners. It is two different forces and needs two different fixes.
All the best,
Study the history of naval architecture and move forward knowing what didnít work before.
Donít waste time making the same old mistakes but instead make new ones and to insure your place in history be sure the mistakes are big ones.
Never design a mast that is weaker then the boat
Never design a boat that is weaker then the mast
Never listen to someone describe why your project will not work unless they can show you the broken pieces of their own version.